Communications Connections; Wiring; Terminal Designations - Hoffer Flow Controls HIT-2A User Manual

4-3

Communications Connections

Communications with the HIT-2A using a terminal or a PC using the
Windows configuration program requires the use of the HOFFER
HIT2A-301 Communications Cable. The communication circuits of
the HIT-2A are externally powered and the power for these circuits is
supplied by the RS232 serial port of the computer/terminal. The serial
port configuration must be set to the following:
Handshaking:
DB9
CD 1
Rx 2
Tx 3
DTR 4
SIG COM 5
Hoffer HIT2A-301 Communications Cable
4-4

Wiring

When connecting the HIT-2A, it is good practice to use shielded cable.
The shield should be connected to earth ground near the instrument.
The other end of the shield should not be connected.
In order to comply with the requirements for Electromagnetic
Compatibility, as per EMC-Directive 89/336/EEC of the Council of
European Community, this wiring practice is mandatory.
4-5

Terminal Designations

Terminal Description
1 Signal/Pulse Input (+)
2 Signal/Pulse Input (-)
3 Shield
4 Reset Input
5 VDC (+)
6 VDC (-) / Reset Common
7 Pulse out (-)
8 Pulse out (+)
9 Alarm (-)
10 Alarm (+)
11 4-20 mA (-)
12 4-20 mA (+)
Baud rate:
Data bits:
Parity:
Stop bits:
VDC1
6 DSR
7 RTS
VDC2
8 CTS
9 NC
2400
8
none
1
None
Installation
Molex
0511100660
or
Equivalent
Pin 1
HP-306
17
Pin 2